Semiconductor devices are used in many electronic and other applications. Semiconductor devices comprise integrated circuits that are formed on semiconductor wafers by depositing many types of thin films of material over the semiconductor wafers and patterning the thin films of material to form the integrated circuits.
Metallization layers are usually the top-most layers of semiconductor devices. While some integrated circuits have a single top layer of metallization, other integrated circuits comprise multi-level interconnects, wherein two or more metallization layers are formed over a semiconductor wafer or workpiece. The metallization layers typically comprise layers of conductive lines separated from one another by an insulating material, also referred to as an inter-level dielectric (ILD) or an inter-metallization dielectric (IMD). Advanced semiconductor processes utilize inter-level dielectrics with low dielectric constants (k) and/or ultra-low dielectric constants (ULK) to minimize interconnect parasitic capacitances.
One of the challenges in semiconductor technology requires developing technologies with good product yield and reliability. However, materials with low dielectric constants generally have poor mechanical properties and are often brittle. Typically, a blade mounted on a rotating spindle coupled to a motor is used in a sawing process used to singulate or separate the wafer into individual dice. During the sawing process, stress may be created in the dicing lanes and adjacent regions. The stress may cause cracks that propagate into circuit elements causing fatal defects. While sawing to singulate the wafer into individual dice often causes chipping on the wafer and/or encapsulant, the low-k dielectric materials tend to be more prone to chipping and hence presents some unique challenges. Oftentimes designers utilize a wider scribe line to allow for the increase chipping, but this reduces the amount of silicon area available for IC fabrication.
These problems may also be present in 3D integrated circuits (ICs). Generally, 3D ICs may be fabricated by vertically stacking dies on a wafer (die-to-wafer) or a wafer on another wafer (wafer-to-wafer). Once stacked, a sawing process may be performed to form separate 3D IC packages. During the sawing process, chipping or cracking, particularly with the low-k dielectrics, may occur. The chipping or cracking may propagate to circuit elements causing failure.